Distributed process control systems, like those used in chemical, petroleum, industrial or other process plants to manufacture, refine, transform, generate, or produce physical materials or products typically include one or more process controllers communicatively coupled to one or more field devices via analog, digital or combined analog/digital buses, or via a wireless communication link or network. The field devices, which may be, for example, valves, valve positioners, switches and transmitters (e.g., temperature, pressure, level and flow rate sensors), are located within the process environment and generally perform physical or process control functions such as opening or closing valves, measuring process and/or environmental parameters such as temperature or pressure, etc. to control one or more processes executing within the process plant or system. Smart field devices, such as the field devices conforming to the well-known Fieldbus protocol may also perform control calculations, alarming functions, and other control functions commonly implemented within the controller. The process controllers, which are also typically located within the plant environment, receive signals indicative of process measurements made by the field devices and/or other information pertaining to the field devices and execute a controller application that runs, for example, different control modules which make process control decisions, generate control signals based on the received information and coordinate with the control modules or blocks being performed in the field devices, such as HART®, WirelessHART®, and FOUNDATION® Fieldbus field devices. The control modules in the controller send the control signals over the communication lines or links to the field devices to thereby control the operation of at least a portion of the process plant or system, e.g., to control at least a portion of one or more industrial processes running or executing within the plant or system. For example, the controllers and the field devices control at least a portion of a process being controlled by the process plant or system. I/O devices, which are also typically located within the plant environment, typically are disposed between a controller and one or more field devices, and enable communications there between, e.g. by converting electrical signals into digital values and vice versa. As utilized herein, field devices, controllers, and I/O devices are generally referred to as “process control devices,” and are generally located, disposed, or installed in a field environment of a process control system or plant.
Information from the field devices and the controller is usually made available over a data highway or communication network to one or more other hardware devices, such as operator workstations, personal computers or computing devices, data historians, report generators, centralized databases, or other centralized administrative computing devices that are typically placed in control rooms or other locations away from the harsher field environment of the plant, e.g., in a back-end environment of the process plant. Each of these hardware devices typically is centralized across the process plant or across a portion of the process plant. These hardware devices run applications that may, for example, enable an operator to perform functions with respect to controlling a process and/or operating the process plant, such as changing settings of the process control routine, modifying the operation of the control modules within the controllers or the field devices, viewing the current state of the process, viewing alarms generated by field devices and controllers, simulating the operation of the process for the purpose of training personnel or testing the process control software, keeping and updating a configuration database, etc. The data highway utilized by the hardware devices, controllers and field devices may include a wired communication path, a wireless communication path, or a combination of wired and wireless communication paths.
As an example, the DeltaV™ control system, sold by Emerson Process Management, includes multiple applications stored within and executed by different devices located at diverse places within a process plant. A configuration application, which resides in one or more workstations or computing devices in a back-end environment of a process control system or plant, enables users to create or change process control modules and download these process control modules via a data highway to dedicated distributed controllers. Typically, these control modules are made up of communicatively interconnected function blocks, which are objects in an object oriented programming protocol that perform functions within the control scheme based on inputs thereto and that provide outputs to other function blocks within the control scheme. The configuration application may also allow a configuration designer to create or change operator interfaces which are used by a viewing application to display data to an operator and to enable the operator to change settings, such as set points, within the process control routines. Each dedicated controller and, in some cases, one or more field devices, stores and executes a respective controller application that runs the control modules assigned and downloaded thereto to implement actual process control functionality. The viewing applications, which may be executed on one or more operator workstations (or on one or more remote computing devices in communicative connection with the operator workstations and the data highway), receive data from the controller application via the data highway and display this data to process control system designers, operators, or users using the user interfaces, and may provide any of a number of different views, such as an operator's view, an engineer's view, a technician's view, etc. A data historian application is typically stored in and executed by a data historian device that collects and stores some or all of the data provided across the data highway while a configuration database application may run in a still further computer attached to the data highway to store the current process control routine configuration and data associated therewith. Alternatively, the configuration database may be located in the same workstation as the configuration application.
Generally, the commissioning of a process plant or system involves bringing various components of the plant or system to the point where the system or plant can operate as intended. As is commonly known, physical process elements (such as valves, sensors, etc. that are to be utilized to control a process in a process plant) are installed at respective locations within the field environment of the plant, e.g., in accordance with Piping and Instrumentation Diagrams (P&IDs) and/or other plans or “blueprints” of the plant floor layout and/or of the process layout. After the process elements have been installed, at least some of the process elements are commissioned. For example, field devices, sampling points, and/or other elements are subject to being commissioned. Commissioning is an involved and complex process which typically includes multiple actions or activities. For example, commissioning may include actions or activities such as, among other things, verifying or confirming an identity of an installed process control device (such as a field device) and its expected connections; determining and providing tags that uniquely identify the process control device within the process control system or plant; setting or configuring initial values of parameters, limits, etc. for the device; verifying the correctness of the device's installation, operation and behaviors under various conditions, e.g., by manipulating signals provided to the devices and performing other tests, and other commissioning activities and actions. Device verification during commissioning is important for safety reasons, as well as to conform to regulatory and quality requirements.
Other commissioning actions or activities are performed on a process control loop in which the device is included. Such commissioning actions or activities include, for example, verifying that various signal sent across the interconnection results in expected behavior at both ends of the interconnection, integrity checks on the process control loop, generating as-built I/O lists to indicate the actual physical connections of the devices that are implemented within the plant as well as recording other “as-installed” data, to name a few.
For some commissioning tasks, a user may utilize a commissioning tool (e.g., a handheld or portable computing device) locally at various target process control devices, components, and loops. Some commissioning tasks may be performed at an operator interface of the process control system, e.g., at an operator interface of an operator workstation included in a back-end environment of the process plant.
Typically, the commissioning of a process plant requires physical devices, connections, wiring, etc. to be installed, set up, and inter-connected in the field environment of the process plant. At the back-end environment of the plant (e.g., at the centralized administrative computing devices such as operator workstations, personal computers or computing devices, centralized databases, configuration tools, etc. that are typically placed in control rooms or other locations away from the harsher field environment of the plant), data that specifically identifies and/or addresses the various devices, their configurations, and their interconnections is integrated, verified or commissioned, and stored. As such, after the physical hardware has been installed and configured, identification information, logical instructions, and other instructions and/or data is downloaded or otherwise provided to the various devices disposed in the field environment so that the various devices are able to communicate with other devices.
Of course, in addition to commissioning actions performed in the back-end environment, commissioning actions or activities are also performed to verify the correctness of the connections and operations in the field environment of both the physical and logical devices, both individually and integrally. For example, a field device may be physically installed and individually verified, e.g., power-on, power-off, etc. A port of a field device may then be physically connected to a commissioning tool via which simulated signals may be sent to the field device, and the behavior of the field device in response to the various simulated signals may be tested. Similarly, a field device whose communication port is commissioned may eventually be physically connected to a terminal block, and actual communications between the terminal block and the field device may be tested. Typically, commissioning of field devices and/or other components in the field environment requires knowledge of component identifications, and in some cases, knowledge of component interconnections so that test signals and responses can be communicated amongst field devices and other loop components and resultant behaviors verified. In currently known commissioning techniques, such identification and interconnection knowledge or data is generally provided to components in the field environment by the back-end environment. For example, the back-end environment will download field device tags that are used in control modules into the field devices that will be controlled by the control modules during live plant operations.
Coupling the field devices' communication ports to the terminal block and, eventually, to the controllers in the back-end environment is generally a complex process. Field devices must be coupled to I/O cards that translate the signals received from the field devices to signals that can be processed by the controllers, and that translate the signals received from the controllers to signals that can be processed by the field devices. Each channel of each I/O card, corresponding to a particular field device, must be associated with the appropriate signal types (so that signals are processed appropriately by the I/O card) and the I/O card must be communicatively coupled to the controller or controllers that will eventually be receiving signals from and/or sending signals to the field devices coupled to that I/O card.
A termination block for a particular area typically serves as the termination point for the wiring (or connection) of field devices from a particular physical area of the process plant, which will be appreciated is a significant amount of wiring in order to couple field devices spread out over an area of a process control facility to the corresponding termination block. A marshaling cabinet in the termination area includes a multiplicity of communication modules that marshal, organize or route signals between the communication modules coupled to the field devices and one or more I/O cards communicatively coupled to the controllers. In addition to the terminal blocks and communication modules, the marshaling cabinet also includes power provisioning to supply power to the I/O cards and the communication modules, power dissipation mechanisms (e.g., heat sinks, fans, etc.) to keep components in the marshaling cabinet from overheating, all of the wiring coming in from the field devices, and various solutions for keeping that wiring from becoming too unwieldy.